RU2635811C2 - Device and method for mixing and stirring and method for manufacturing lightweight gypsum plate - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: device (10) for mixing and stirring for a gypsum solution has a round case (20) forming a mixing area, a rotating disk (32) located in the case, and a tube (50, 90, 95, 96, 97, 97') for feeding the solution to a sheet paper to cover (1) the gypsum plate. The groove has a fluid channel portion (60, 61, 91, 92) and its cross section is non-axisymmetric relative to the central axis (C, C1) of the tubular channel, or a fluid channel portion (98.99) changes the position of the central axis of the tubular channel as a result of a change or lateralization of the fluid channel cross-section. Axisymmetric vortex flow generated in the tubular channel in the form of the twisted intra-tubular flow (F) is torn at the fluid channel portion, and therefore its twisted movement which may lead to inhomogeneity or instability of the density distribution, essentially disappears in the solution (3) poured on a sheet of paper.

EFFECT: prevention of misdistribution, deviation or irregular distribution of the solution density on a sheet of paper.

13 cl, 21 dwg

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a device and method for mixing and mixing, and to a method for manufacturing a lightweight gypsum board, and more particularly, such a device and methods that allow controlling or restricting the swirling movement of gypsum mortar poured onto a sheet of paper to cover the gypsum board in order to maintain a uniform distribution of the density of the gypsum mortar on the sheet.

State of the art

[0002] Gypsum boards are known as boards having a gypsum core coated with sheets of paper as a gypsum board coating and are widely used as various kinds of materials for construction and architectural interior finishing, due to their preferred properties, as fire resistance or protection ability from fire, sound insulation characteristics, workability, cost characteristics and so on. Typically, gypsum boards are produced using a continuous casting and solution casting process. Such a process comprises a mixing and stirring step consisting in mixing calcined gypsum, auxiliary adhesive agent, setting accelerator, foam (or foaming agent), etc. with mixing water in a mixing and stirring device; a forming step consisting in pouring a solution of calcined gypsum prepared in the device (hereinafter referred to as “solution”) into the region between the upper and lower sheets of paper used as a coating of the gypsum board, and forming it using continuous formation in the form of a tape; and the drying and slicing step, performing coarse cutting of the hardened continuous multilayer configuration in the form of a tape, forcing it to be dried, and then slicing to the product size.

[0003] Typically, a thin-type circular centrifugal mixer for preparing a solution is used as a mixing and mixing device. This type of mixer comprises a flattened round casing and a rotating disk mounted rotatably inside the casing. A plurality of material supply ports for supplying the above-described materials to the mixer are located in the central region of the upper cover or upper plate of the housing, and an outlet port for the solution for supplying the mixture (solution) from the mixer is provided on the outer periphery of the housing or on its lower plate (bottom cover). Typically, a rotating shaft is connected to the disk to rotate the disk, and the shaft is connected to the rotation drive means. On the upper plate of the housing there are many upper pins (fixed pins) hanging down from it to the area of direct proximity to the disk. The lower pins (movable pins) are provided on the disk, which are mounted vertically on the disk and which extend upward into the region of close proximity to the upper plate. The upper and lower pins are located in radially alternating positions. The ingredients intended for mixing are fed to the disk through the respective supply ports, and mixed and mixed as they move radially outward along the disk under the action of centrifugal force, and then fed from the mixer through the outlet port for the solution, which is located on the outer periphery or on the bottom plate (bottom cover). A mixer with such an arrangement is called a pin type mixer, which is disclosed, for example, in PCT Application Publication No. WO00 / 56435 (Patent Literature 1).

[0004] With regard to the method of supplying the solution prepared in the mixer, beyond the limits of the mixer, basically, the following three types of methods are known in the art:

1) a vertical gutter, also called a “container”, is mounted on the outlet port for the solution provided on the annular wall of the housing, and the solution from the rotary disk is fed into the gutter by centrifugal force, so that the solution flowing into the gutter is poured under the action of gravity on a sheet of paper (international publication of PCT application No. WO2004 / 026550 (Patent literature 2));

2) the tubular channel for transporting the solution is transversely connected to the outlet for the solution provided on the annular wall of the housing, so that the solution is poured onto a sheet of paper using the feed pressure of the mixer (US Patent Publication No. 6494609 (Patent Literature 3));

3) the tubular channel for supplying the solution is vertically connected to the outlet port for the solution provided on the bottom plate of the housing, so that the solution is spilled by gravity onto a sheet of paper through the feed channel (Japanese Patent Laid-Open Publication No. 2001-300933 (Patent Literature four)).

[0005] Typically, the foam or foaming agent is fed into a solution in a mixer to adjust or correct the specific gravity of the gypsum board. Proper mixing of the foam or foaming agent into the solution is considered an essential element in the method of manufacturing lightweight gypsum boards. Therefore, in a method for producing gypsum boards in recent years, a technology for properly mixing an appropriate amount of foam or foaming agent with a solution is considered to be especially important. With regard to reducing the amount of foam or foaming agent supplied (hereinafter referred to as “the amount of foam”) and uniformly mixing the solution and the foam, it is considered that the relationship between the method of supplying the foam or foaming agent to the solution and the method of supplying the solution is very important (Patent Literature 2 and 3) .

[0006] In each of US Patent Publication No. 6742922 (Patent Literature 5) and PCT International Publication No. WO2004 / 103663 (Patent Literature 6)), a technique is disclosed for maintaining uniform dispersion and distribution of a foam or foaming agent in a solution using swirling flow of solution in a vertical trough.

[0007] In the circular fluid channel in the vertical trough, there is provided an opening element in the lower part of the channel in the mixer device for uniformly dispersing the distribution of foam in the solution using the swirling flow of the solution generated in the trough. The hole element has a hole or restriction (hereinafter referred to as a "hole"). The hole acts as resistance to the fluid against the vertical movement of the solution, so that the solution flowing through the trough does not flow directly down through the trough under the action of gravity, and therefore a swirling flow of the solution is reliably formed in the inner tubular region of the trough.

[Bibliography]

[Patent literature]

[0008] [Patent Literature 1] International Publication of PCT Application No. WO00 / 56435

[Patent Literature 2] International Publication of PCT Application No. WO2004 / 026550

[Patent Literature 3] Publication of US Patent No. 6494609

[Patent Literature 4] Japanese Patent Laid-Open Publication No. 2001-300933

[Patent Literature 5] Publication of US Patent No. 6742922

[Patent Literature 6] International Publication of PCT Application No. WO2004 / 103663

SUMMARY OF THE INVENTION

[Technical Problem]

[0009] The hole of the aforementioned hole element is designed as a horizontal hole in the shape of a perfect circle, the center of which coincides with the central axis of the gutter. As described in Patent Literature 5, the radius of the swirling flow of the solution generated in the upper region above the hole temporarily decreases with its swirling motion and the speed of the fluid in the hole increases, and then, on the side downstream, the radius of the swirling movement of the solution increases , and its fluid velocity is reduced so that the radius and velocity of the swirling flow before entering the hole is practically restored or regenerated. Turbulent flow is locally generated in the region of the hole, as a result of changes in the radius and flow rate, which contributes to the mixing of the solution and the foam.

[0010] However, in experiments performed by the authors of the present invention, it was determined that when measuring the specific gravity of the solution poured from the chute onto a sheet of paper intended to cover the gypsum board, a relatively significant distribution disturbance, deviation or irregular dispersion in the solution density distribution along paper width directions, as shown in the comparative examples in FIG. 14-17. In addition, in accordance with experiments performed by the inventors of the present invention, such a deviation or irregular dispersion was more observed when the amount of foam was increased to reduce the weight of the gypsum board. Therefore, in the case when it was required to produce lightweight gypsum boards, it is especially important to reliably exclude the occurrence of such a violation of the distribution, deviation or irregular dispersion in the distribution of specific gravity.

[0011] In addition, the disclosed technology in Patent Literature 5 and 6 is directed to an arrangement that facilitates mixing of the solution and the foam using a swirling flow generated by the in-tube region of a trough having a vertical central axis. A similar phenomenon was also observed in the tubular channel for transporting the solution, transversely connected to the outlet for the solution on the annular wall of the housing (Patent Literature 3), or in the tubular channel for supplying the solution, vertically connected to the outlet for the solution on the bottom plate of the housing (Patent literature 4)), in which a swirling flow occurred in the port for discharging the solution of the tubular channel when the solution was spilled onto a sheet of paper.

It is believed that this is due to the effect of the rotational movement of the solution in the internal mixing region of the mixer, the axisymmetric swirling flow generated as a swirling flow of the solution inside the pipe in the in-tube region of the tubular channel, etc.

[0012] An object of the present invention is to provide an apparatus and method for mixing and stirring and a method for manufacturing a lightweight gypsum board that can limit the swirling movement of gypsum mortar spilled onto a sheet of paper to cover the gypsum board, thereby preventing a disturbance distribution, deviation or irregular dispersion in the distribution of the specific gravity of the solution on a sheet of paper.

[The solution of the problem]

[0013] The present invention is directed to a gypsum mortar mixing and stirring device, which has a round body in which a mixing region is formed for mixing gypsum mortar, a rotating disk mounted in the body and rotating in a predetermined rotation direction, and a tubular feed channel gypsum mortar supplied outward from the housing for supplying mortar from the mixing area to a sheet of paper intended to cover the gypsum board in which said tubular channel is included includes a portion of the fluid channel having an axisymmetric cross section with respect to the central axis of the tubular channel for rupturing the axisymmetric vortex flow of gypsum mortar generated in the tubular channel as a swirling tube, or a portion of the fluid channel in which the position of the central axis the tubular channel as a result of changing the laterization of the cross section of the fluid to form a rupture action with respect to said axisymmetric vortex th stream.

[0014] The present invention is also directed to a method for mixing and stirring a gypsum mortar using a device for mixing and stirring a gypsum mortar having a round body in which a mixing area for mixing gypsum mortar is formed, a rotating disk mounted in the body and rotating in a predetermined direction of rotation, and a tubular channel for supplying gypsum mortar supplied outward from the housing for supplying mortar from the mixing area to a sheet of paper intended for I cover the gypsum board containing the following steps:

form a section of the channel for the fluid in the form of a tubular channel, the cross section of which is made axisymmetric relative to the Central axis of the said tubular channel, or a section of the channel for the fluid of the tubular channel, in which the position of the Central axis of the tubular channel changes as a result of changing or laterization of the cross section of the channel for the fluid environment; and

discontinuing the axisymmetric vortex flow, which is generated in the said tubular channel in the form of a swirling in-tube flow, by changing the cross section and / or center of the fluid channel, thereby limiting the regeneration or generation of the swirling channel inside the pipe in the in-tube region of the outlet pipe section of the aforementioned a tubular channel, which is located on the side downstream of the channel for the fluid.

[0015] As the authors of the present invention understand, heterogeneity, instability, etc. with respect to the density distribution of the solution poured onto a sheet of paper, a phenomenon occurs in which the components of the mixture having a relatively high specific gravity are displaced to the outer portion of the swirling flow, and the components of the mixture having a relatively low specific gravity are shifted to the inner portion of the swirling stream , as a result of the action of a swirling intratubular flow generated in the tubular channel for supplying the solution.

Therefore, in the case where the solution includes a relatively large amount of foam or foaming agent, which has a relatively low specific gravity, a significant phenomenon of heterogeneity or instability is observed. In accordance with the present invention, an axisymmetric vortex stream generated as a swirling in-tube stream in a tubular channel for supplying a solution is torn at least partially using a non-axisymmetric cross section of the fluid channel or a change or laterization of the cross section of the fluid channel, to change the position of the center of the tubular channel, as a result of which, the tubular channel is substantially disturbed in such a portion of the fluid channel. Thus, the swirling in-tube flow after the channel through this section of the fluid channel does not restore its state before entering this section of the channel, or the swirling flow is hardly generated in the section of the subsequent side of the fluid channel. The swirling movement practically disappears on the portion of the subsequent side of the fluid channel, and the swirling movement, which may be the cause of the heterogeneity or instability of the specific gravity distribution, is not stored in the solution, which is poured from the outlet pipe portion onto a sheet of paper. In accordance with experiments performed by the inventors of the present invention, when a solution with limited swirling motion is poured onto a sheet of paper, the specific gravity distribution becomes uniform and stable even when the solution includes a relatively large amount of foam or foaming agent, and, therefore, the above-mentioned problem of heterogeneity or instability of the density distribution can be overcome.

[0016] The term “rupture” does not always mean complete rupture of the axisymmetric vortex flow, but it means that the axisymmetric vortex flow is at least partially broken to the extent that regeneration or the formation of a swirling flow at the outlet of the pipe through which or pour the solution onto a piece of paper.

In addition, the term “fluid channel cross section” means a cross section perpendicular to the direction of flow of the gypsum mortar.

[0017] From another aspect of the invention, the present invention provides a method for manufacturing lightweight gypsum boards having a specific gravity equal to or less than 0.8, in which the gypsum mortar is produced using a gypsum mortar mixing and mixing device that has a round body, in which a mixing region is formed for mixing the gypsum mortar, a rotating disk located in the housing and rotating in a predetermined direction of rotation, and a tubular channel for supplying the obtained gypsum mortar for thinned body, for supplying the solution from the mixing region to a paper sheet used as a coating the gypsum board, and wherein the mixing area of the solution is dispensed onto said sheet of paper comprising the steps of:

the said gypsum mortar is fed from the mixing area, flowing out of the housing through the solution outlet port located on the housing, into said tubular channel together with foam or foaming agent, to control the specific gravity, and a swirling flow is generated inside the pipe in the inner tube region of the tubular channel, the rotation of the solution in it so that the solution and the foam or foaming agent are mixed in the tubular channel under the action of a swirling flow generated in the tubular channel; and

forming a portion of the fluid channel in said tubular channel, which has a cross section for the tubular channel, which is not axisymmetric with respect to the central axis of the tubular channel, or in which the central axis of the tubular channel changes as a result of a change or laterization of the cross section of the tubular channel, and this leads to a rupture axisymmetric vortex flow swirling intratubular flow generated in the said tubular channel, as a result of changes in the cross section of the channel A fluid and / or its center, which limits or regeneration occurrence vnutritrubchatogo swirling flow in the outlet tube portion of said tubular channel which is located on the downstream side of said fluid channel area.

Preferably, a channel with an opening is provided in the tubular channel, which has a cross-section for the fluid channel that is not axisymmetric with respect to the central axis of the tubular region and which locally limits the cross-section of the fluid channel, and the axisymmetric vortex breaks in the region inside the tubular region in the channel with the hole, to limit the regeneration or generation of swirling in-tube flow at the outlet of the pipe of the tubular channel, which is located one hundred Rone downstream of the channel with the hole.

[0018] According to the above arrangement of the present invention, the solution and the foam or foaming agent are mixed in a swirling in-tube flow generated in the tubular channel, and the foam or foaming agent in the solution tends to radially displace inward to the swirling flow. However, the occurrence of such a displacement of the foam or foaming agent is prevented as a result of the rupture of the axisymmetric vortex flow caused by the flow of fluid through the above-mentioned section of the fluid channel or the channel with the hole. Since the portion of the fluid channel or the channel with the hole restricts the regeneration or generation of the vortex in-tube flow in the downstream portion of the pipe, the solution is poured onto a sheet of paper from the outlet of the pipe in a state in which the foam or foaming agent is uniformly distributed in the solution. The authors of the present invention determined during experiments that it is possible to prevent distribution disturbance, deviation or irregular dispersion in the distribution of specific gravity, even when the specific gravity of the gypsum core of the gypsum board is significantly reduced (for example, when the mixing ratio of materials and production conditions corresponding to the specific weight 0.4), as shown in the examples in FIG. 14-17.

[Preferred effects of the invention]

[0019] In accordance with the present invention, a device and method for mixing and stirring, and a method for manufacturing a lightweight gypsum board can be provided that can limit the rotational movement of the gypsum mortar spilled onto a sheet of paper used as a gypsum board coating, preventing as a result, incorrect distribution, deviation or irregular dispersion in the distribution of the specific gravity of the solution on a sheet of paper.

Brief Description of the Drawings

[0020] FIG. 1 is an explanatory flowchart partially and schematically illustrating gypsum board forming processing.

In FIG. 2 is a partial plan view schematically illustrating an arrangement of a gypsum board manufacturing apparatus.

In FIG. 3 is a plan view illustrating the general arrangement of the mixer, as shown in FIG. 1 and 2.

In FIG. 4 is a perspective view illustrating a general arrangement of a mixer.

In FIG. 5 is a partial cross-sectional view showing an internal structure of a mixer.

In FIG. 6 is a vertical cross-sectional view showing the internal structure of the mixer.

In FIG. 7 is a perspective view with a cross section of a fragment representing the internal structure of the mixer.

In FIG. 8 is a cross-sectional view and a perspective view of a vertical groove.

In FIG. 9 is a longitudinal sectional view of a vertical trough.

In FIG. 10 is a plan view of a hole element.

In FIG. 11 is a cross-sectional view of an opening element along line I-I of FIG. 10.

In FIG. 12 is a cross-sectional view of a trough having an opening element in accordance with a comparative example.

In FIG. 13 is a longitudinal sectional view of the trough, as shown in FIG. 12.

In FIG. 14 is a graphical diagram showing the results of measuring the specific gravity distribution with respect to gypsum cores, in which the target specific gravity of the core is 0.7.

In FIG. 15 is a graphical diagram showing the results of measuring the specific gravity distribution with respect to gypsum cores in which the target specific gravity of the core is 0.6.

In FIG. 16 is a graphical diagram showing the results of measuring the specific gravity distribution with respect to gypsum cores, in which the target specific gravity of the core is 0.5.

In FIG. 17 is a graphical diagram showing the results of measuring the specific gravity distribution with respect to gypsum cores, in which the target specific gravity of the core is 0.4.

In FIG. 18 is a plan view showing a contour change in plan of the opening of FIG. 10.

In FIG. 19 is a plan view showing the relationship between the hole and the central circular region.

In FIG. 20 is a partial perspective view of hole elements that represent configurations of hole edge portions.

In FIG. 21 is a schematic perspective view and a cross-sectional view illustrating arrangements for changing or deflecting a cross section of a fluid channel or decentralizing a fluid channel.

DETAILED DESCRIPTION OF THE INVENTION

[0021] In a preferred embodiment of the present invention, the portion of the fluid channel is an orifice with a hole locally limiting the cross section of the fluid channel, and the channel with an orifice has a centroid of its cross section located in an eccentric position with respect to the central axis of the tubular channel. Preferably, the cross-sectional contour of the channel with the hole is a single figure or a composite figure made up of a plurality of figures partially overlapped. The centroid of the figure or composite figure is eccentric relative to the central axis of the tubular channel. For example, a composite figure consists of many circles (a perfect circle, an ellipse, an elongated circle, etc.) having different diameters and / or different positions of the centers that are overlapped only partially (the composite figure does not include figures having the same central position and are completely superimposed on each other, or consisting of two circles having one circle completely inscribed in another circle, and so on).

[0022] In the present invention, the eccentricity ratio “η = ΔE / r” of the centroid is preferably set to a range equal to or greater than 0.06 (6%), in which the eccentricity ratio “η” of the centroid is defined as “ΔE / r” , “ΔE” represents the distance between the centroid and the central axis of the tubular channel, and “r” represents the radius of the tubular channel. If required, the eccentricity ratio “η” can be set equal to or greater than 0.10 (10%). The centroid eccentricity ratio “η” can be defined as “ΔE / Rmax”, in which “Rmax” is the maximum distance from the central axis of the tubular channel to the outline of the figure. In this case, the eccentricity ratio “η” is preferably set equal to or greater than 0.10 (10%), and if desired, the eccentricity ratio “η” can be set to equal to or greater than 0.15 (15%). In accordance with experiments made by the authors of the present invention, such values of the eccentricity of the channel with the hole do not prevent the formation of a swirling flow on the previous side of the channel with the hole.

[0023] According to a preferred embodiment of the present invention, gypsum board materials including calcined gypsum, water and additive mixes, and additives (such as an adhesive agent, setting accelerator and so on) are supplied to the mixing and mixing apparatus . These ingredients are mixed with each other, moving radially outward along the disk under the action of centrifugal force, and reach the peripheral zone (solution retention area) of the device, as the solution is essentially completely mixed. For example, the output port is located on the annular wall of the round casing so that the centrifugal force of the device acts on it. The specific gravity of the gypsum mortar depends on the amount of foam added, unless a factor representing the amount of mixing water is taken into account. Preferably, a port for supplying foam through which foam or a foaming agent is supplied to the solution for controlling the specific gravity of the gypsum core is located on the annular wall, so that foam or foaming agent is fed into the solution immediately before the solution flows into the outlet port for the solution from the mixing area; or a foam supply port is located in the solution supply area, such that the foam or foaming agent is supplied to the solution immediately after the solution flows through the solution outlet port from the mixing area. Thus, the foam mixed in the solution can be lost due to the quenching of the foam or the destruction of the foam due to exposure to the mixing and stirring device during mixing, but the required amount of foam or foaming agent can be significantly reduced by applying foam or the foaming agent into the solution at the final stage of preparation of the solution, since the foam or the foaming agent is not affected by mixing (therefore, the foam is effectively mixed with the solution).

[0024] Preferably, the tubular channel includes a chute into which gypsum mortar flows out of the housing through an outlet port for the housing solution. The trough forms an axisymmetric vortex flow around its vertical central axis in its in-tube region. The output part (lower part) of the trough is connected to a section of the outlet pipe through which the gypsum solution is poured onto a sheet of paper. The solution generates a vortex intratubular flow in the tubular channel or in the trough, in accordance with the variation of the cross section of the fluid channel, the direction of the fluid flow, the speed of the fluid, etc., when the solution flows through the outlet ports for the solution from the mixing area, when the solution flows into the in-tubular region between the outlet port for the solution and the trough, or when the solution enters the trough. As a result, an axisymmetric vortex flow is formed in the in-tube region of the trough around its vertically extending central axis. The channel through the hole is located in the lower region of the trough, so that it breaks the axisymmetric vortex flow, which, under the action of gravity, moves downward in the intratubular region. With this arrangement, the solution and the foam or foaming agent can be mixed in the tubular region of the trough under the action of a swirling flow in the trough, and the swirling flow moves downward by gravity, where it ruptures in the channel with the hole, preventing the swirling flow from regenerating or generating at the outlet pipes on the downstream side or on the lower side of the channel with the hole. As a result, uniformity of the specific gravity of the solution is poured onto a sheet of paper. In one embodiment of the present invention, the outlet port of the solution is located on the annular wall or on the peripheral wall of the housing, or on the bottom plate or bottom cover of the housing, and the upper part of the gutter communicates with the outlet port for the solution through a tubular housing such as a polymer resin pipe. In addition, if desired, the central axis of the gutter can be tilted relative to the vertical direction.

[0025] According to a preferred embodiment of the method for making lightweight gypsum boards, foam or foaming agent is supplied to the solution immediately before or immediately after the solution flows through the solution outlet port from the mixing area, and the amount of foam or foaming agent supplied to the solution is set as the amount to obtain the gypsum core of the gypsum board having a specific gravity in the range from 0.4 to 0.7.

[0026] Preferably, the element with the hole, with the channel with the hole is located in the tubular channel, and the element with the hole has adjusting means for regulating the cross section of the channel for the fluid that rotates or moves in the element with the hole, for regulating or controlling the intensity of the action of the axisymmetric rupture vortex in the channel with a hole. In such a regulating means, the regulation of the intensity of action can be influenced by adjusting or setting the cross section of the channel with the hole. In a mixing and stirring device having such a channel with an opening and its regulating means, the action of the channel with the opening can be precisely controlled or changed by means of regulating means, while the state or physical property of the solution supplied to the sheet of paper is observed or measured during device operation. In practice, this is very preferred. During experiments performed by the inventors of the present invention, as described below, the state or physical property of the solution supplied to the sheet could be changed when the element with the hole was rotated around the central axis of the tubular channel by at least 3 (three) degrees. Thus, during the experiments performed by the authors of the present invention, it was determined that the intensity of the action of the rupture of the axisymmetric vortex can be variably controlled, or it could be controlled by rotating the hole element by an angle of at least 3 degrees.

[0027] In another embodiment of the present invention, the tubular channel is a tubular channel for transporting the solution, which is connected to the outlet port for the solution on the annular wall of the housing and extends transversely from it, or a tubular channel for supplying the solution, which is connected to the outlet port for the solution the bottom plate of the case and hangs from it. The subsequent ends of these channels constitute sections of the outlet pipe for the solution, along which the solution is poured onto a sheet. A channel with holes is provided in the tubular channel to break the axisymmetric vortex flow generated as a swirling in-tube flow in the channel.

Option exercise

[0028] Preferred embodiments of the present invention will be described below with reference to the attached drawings.

[0029] FIG. 1 is an explanatory processing diagram partially and schematically illustrating gypsum board forming processing, and FIG. 2 is a partial plan view schematically illustrating an arrangement of a gypsum board manufacturing apparatus.

[0030] A bottom sheet of paper 1, which is a sheet of paper for coating a gypsum board, is fed along a production line. The mixer 10 is located in a predetermined position relative to the conveyor line, for example, in a position above the conveyor line. Powder materials P (calcined gypsum, an adhesive agent, setting accelerator, additives, impurities, etc.) and liquid (water) L are supplied to mixer 10. In mixer 10, these materials are mixed and a solution (calcined gypsum solution) 3 is removed per sheet 1 through the solution supply section 4, the solution outlet pipe 7 and the fractionation pipes 8 (8a, 8b).

Section 4 of the output of the solution is located so that it enters the solution discharged from the peripheral zone of the mixer 10 and through it, the solution enters the pipe 7. Foam M formed by means of foam (not shown) is fed into section 4. The pipe 7 is installed so that when it flows through it, the solution spills from section 4 into the central region along the width of sheet 1 (core region) through the port (hole) 70 for discharging the solution. Pipelines 8a, 8b are arranged such that they spill into the end sections along the width (edge zone) of the sheet 1 of solution 3 coming from the peripheral region of the mixer 10. Instead of foam M, the foaming agent can be directly fed into the solution, so that the foam may form in solution as a result of the foaming action of the foaming agent in the solution.

[0031] Sheet 1 is moved together with solution 3 so that it reaches a pair of forming rollers 18 (18a, 18b). The upper sheet of paper 2 is moved partially along the periphery of the upper roller 18a, so that the direction of movement of the sheet is converted to the direction of transportation. The deflected sheet 2 is brought into contact with the solution 3 on the bottom sheet 1 and moved in the direction of transportation, so that it is located essentially parallel to the bottom sheet 1. A continuous three-layer configuration 5 in the form of a tape, consisting of sheets 1, 2 and solution 3 , is formed on the side downstream of the rollers 18. This configuration 5 moves continuously with the transport speed V, while in solution 3, a reaction occurs until it reaches the coarse cut rollers 19 (19a, 19b). If desired, a plurality of forming means can be used in place of the forming rollers 18, such as forming means that use the action of a through channel in the form of an extruder, a shutter with a rectangular hole, etc.

[0032] The cutting rollers 19 perform coarse cutting of a continuous configuration, forming panels of a given length, so that panels having a gypsum core are coated with sheets of paper, that is, blank panels. Then, the blank panels are moved through a drying device (not shown), which is located in the direction shown by the arrow J (on the downstream side in the transport direction), as a result, the blank panels are forced dried in the drying device. After that, they are cut into slabs, each of which has a predetermined product length, and thus the product is subsequently produced in the form of a gypsum board.

[0033] FIG. 3 and 4 are plan and perspective views illustrating the entire arrangement of the mixer 10, and FIG. 5, 6 and 7 show views in cross section and in a vertical section and views in perspective with a fragment in section, representing the internal structure of the mixer 10.

[0034] As shown in FIG. 3 and 4, the mixer 10 has a tapered cylindrical body or body 20 (hereinafter referred to as “body 20”). The housing 20 has a horizontal top plate in the form of a disk or a top cover 21 (hereinafter referred to as a “top plate 21”), a horizontal bottom plate in the form of a disk or a bottom cover 22 (hereinafter referred to as a “bottom plate 22”), and an annular wall or an outer peripheral wall 23 (hereinafter referred to as the "annular wall 23"), which is located on the peripheral portions of the upper and lower plates 21, 22. The plates 21, 22 are located, being separated vertically from each other at a predetermined distance, so that an internal mixing region 10a is formed, for laugh sewing powder materials P and liquid (water) L in the mixer 10. A circular hole 25 is formed in the central part of the upper plate 21. The enlarged lower end portion 31 of the rotating vertical shaft 30 extends through the hole 25. The shaft 30 is connected to the rotation drive means, such as an electric drive motor (not shown), and driven in a predetermined rotation direction (clockwise direction γ, as can be seen from its upper side, in this embodiment). If desired, a speed changing device, such as a gear mechanism or a belt speed changing unit, may be located between the shaft 30 and the output shaft of the rotational drive means.

[0035] A pipe 15 for supplying powder to the supply area 10a for supplying powder materials P for mixing is connected to the upper plate 21. A water supply pipe 16 for supplying a certain amount of mixing water L to the area 10a is also connected with the upper plate 21. If required, an internal pressure regulator (not shown), to limit the excessive increase in internal pressure, etc., can be additionally connected to the upper plate 21.

[0036] On the opposite side of section 4, fractionation ports 48 (48a, 48b) are provided on the annular wall 23. Pipelines 8a, 8b are connected to ports (holes) 48a, 48b, respectively. Ports 48a, 48 are located at a distance set through a predetermined angle from each other. The feed ports of the pipelines 15, 16 displayed in the range of angle α in the Central region of the upper plate 21, respectively.

[0037] As shown in FIG. 5, the outlet port 45 for the solution in the solution supply section 4 is located on the annular wall 23 spaced at a predetermined angle β from the fractionation port 48a in the rotation direction γ (on the downstream side). Port 45 is brought out on the inner surface of the wall circumference 23. A pipe 40 for supplying foam, through which foam M is fed into the solution, for regulating the specific gravity of the solution, is connected to part 47 of the hollow connector of section 4. Port (hole) 41 for supplying foam in the pipe 40 is output on the inner wall surface of the connector portion 47. Port 41 is located on the downstream side of the port (opening) 45 in close proximity to it. If necessary, ports for supplying foam (not shown) can be additionally provided in ports 48 (48a, 48b), for supplying foam M to the solution, for controlling the specific gravity of the solution.

[0038] As shown in FIG. 5-7, the rotary disk 32 is rotatably mounted in the housing 20. The lower surface of the end portion 31 of the shaft 30 is rigidly fixed to the central part of the disk 32. The central axis 10b of the disk 32 coincides with the axis of rotation of the shaft 30. The disk 32 rotates with the rotation of the shaft 30 in the direction indicated by the arrow γ (clockwise direction).

[0039] A plurality of lower pins (movable pins) 38 are located on the rotary disk 32 in a plurality of rows extending generally in its radial direction. The lower pins 38 are mounted vertically on the upper surface of the disk 32 in its inner zone. A plurality of gear configurations 37 are formed on the disk 32 in its peripheral zone, in this embodiment. The gear configurations 37 act so that they displace or give energy to the mixed fluid (solution) outward or in the direction of rotation. A plurality of pins 36 are vertically mounted on each of the gear configurations 37.

[0040] As shown in FIG. 6 and 7, a plurality of upper pins (fixed pins) 28 are mounted on the upper plate 21, so that they hang from it into the inner mixing region 10a. The upper pins 28 and lower pins 38 are arranged alternately in the radial direction of the disk 32 so that the pins 28, 38 perform relative movements to mix and mix the gypsum board materials in the housing 20 when the disk rotates.

[0041] When gypsum boards are produced, the rotational drive of the mixer 10 operates to rotate the rotary disk 32 in the direction of arrow γ, and the ingredients (powder materials) P and mixing water L, which are to be mixed in the mixer 10, are supplied to the mixer 10 through a conduit 15 for supplying powder and a conduit 16 for supplying water. The ingredients and water enter the inner region of the mixer 10, mix in it and mix with each other during radial outward movement on the disk 32 under the action of centrifugal force and move along the circumference in the peripheral zone.

[0042] A portion of the solution produced in the region 10a flows into the pipelines 8a, 8b through the fractionation ports 48a, 48b, and the solution is discharged through the pipelines 8a, 8b to the edge zones of the bottom sheet 1 (Fig. 1). In this embodiment, none of the ports 48a, 48b has a foam supply port, and therefore, the solution 3b (FIG. 2) entering the edge zones through ports 48a, 48b that does not contain foam has a relatively high specific gravity , compared with the solution 3a (Fig. 2) entering the core zone through part 47 of the hollow connector. If a foam port (not shown) is provided on each of the ports 48a, 48b, a small amount of foam is supplied to the solution in each of the ports 48a, 48b. Even so, the solution 3b entering the edge zones through the ports 48a, 48b usually has a relatively large specific gravity compared to the solution 3a entering the core zone through the portion 47 of the hollow connector.

[0043] A large part of the solution formed in the mixing region 10a is moved outward and forward in the rotation direction by the gear configurations 37, and the solution flows out through the solution outlet port 45 in the solution supply section 4, in a direction approximately tangential as shown by arrows in partially an enlarged view of FIG. 5. The hollow connector portion 47 is made of a vertical side wall 47a on the preceding side, a vertical side wall 47b on the downstream side, a horizontal upper wall 47c, and a horizontal lower wall 47d. Wall 47a extends approximately in a direction tangential to the annular wall 23. Port 45 and connector portion 47 are brought into the inner mixing region 10a of mixer 10, so that they enter the solution from region 10a, generally approximately in the tangential direction. The solution supply section 4 further includes a vertical groove 50 having a cylindrical shape. The preceding open end of the connector portion 47 is connected to an edge portion of the port 45. The subsequent open end of the portion 47 is connected to an upper hole 55 formed in the upper portion of the cylindrical wall of the groove 50.

[0044] The solution flows into the fluid channel 46 of the solution of the connecting portion 47 from the port 45, and then flows along the vertical groove 50 through the holes 55. The foam supply port 41 is located on the wall 47a on the preceding side in the direction of rotation, so that the foam M enters the solution immediately after it is fed into channel 46 through port 45.

[0045] As shown by dashed lines in FIG. 5, the foam supply conduit 40 can be replaced by a foam supply conduit 40 'that is connected to the annular wall 23 and which has a foam supply port (hole) 41' that extends to the inner surface of the round wall in the wall 23. With this arrangement for supplying foam the foam is fed into the solution, which immediately flows out through port 45. The solution in the peripheral zone into which the foam is fed, immediately flows through port 45 into the channel 46, approximately in the direction tangentially, immediately after the foam is mixed into the solution and then the solution is about ekaet the trough 50 of channel 46.

[0046] As shown in FIG. 5, the vertical groove 50 has an inner region D located on the preceding side of the hole element 60 (hereinafter referred to as “the preceding inner region D”), and the preceding inner region D has a circular cross-section with a radius r, the center of which is a vertically extending central axis C The connector portion 47 is connected to the groove 50 in an eccentric state on one side (in a position eccentric on the side adjacent to the wall 23 in this embodiment). Therefore, the channel 46 is brought to the previous inner region D in a position eccentric on one side. In this invention, the chute may have a central axis C inclined with respect to the vertical direction.

Furthermore, as shown by dashed lines in FIG. 5 and 6, one end (preceding end) of the pipe 47 ', 47 ", such as a polymer resin pipe, can be connected to a solution outlet port provided in the annular wall 23 or on the lower plate 22, and the other end (subsequent end) ) pipes 47 ', 47 "can be led into the upper space of the gutter.

[0047] The solution and the foam entering the preceding inner region D rotates around the central axis C of the groove 50, so that the solution swirls around the inner surface of the round wall of the region D. Due to the swirling or rotational movement of the solution in region D, onto the solution and shear forces the foam, causing them to mix with each other so that the foam is evenly distributed in the solution. The solution in the chute 50 under the influence of gravity flows down so that it is released into the Central region in the direction of the width of the bottom sheet 1 through the pipe 7 (Fig. 1). Thus, part 47 of the chute 50 and pipe 7 constitute a tubular channel for supplying the solution to a sheet of paper intended to cover the gypsum board.

[0048] FIG. 8 and 9 are a cross-sectional view, a perspective view, and a vertical sectional view showing the structure of a vertical groove 50, in which the housing 20 and part 47 of the connector are shown as imaginary lines (dashed lines).

[0049] The vertical trough 50 is made of a cylindrical body 51 made of metal, and has a radius r (inner size), a circular upper plate 52 made of metal, and covering the circular upper hole of the housing 51, the circular flange portion 53 integrally extending outward the periphery of the lower end edge of the housing 51, and the hole element 60 located on the lower portion of the previous inner region D. The exhaust pipe 7, which is an L-shaped pipe made of rubber or polymer resin, and which is also called “boot (s)”, connected in series with the subsequent side of the groove 50. The pipe 7 includes a vertical tubular section 71 and an annular flange portion 72 integrally extending outward from the periphery of the upper end edge of the tubular portion 71. The flange portion 72 is sandwiched between section 53 of the flange and the annular metal plate 76 under the action of the clamping force of the nodes 77 of the bolt-nut, so that the tubular section 71 and the housing 51 are integrally connected to each other. The pipe 7 further includes a portion 73 of the bent pipe (bent pipe), which is a continuous extension of the tubular portion 71, and a transversely extending tubular portion 74 that continuously extends from the portion 73. The tubular portion 74 is routed to the mortar discharge port 70 (FIG. . 2).

[0050] The hole member 60 is an integrally formed metal product that generally has a flattened column configuration. The hole element 60 has a hole 61, designed to provide a connection between the preceding inner region D of the chute 50 and the inner region K of the pipe 7 on the downstream side of the hole element 60 (hereinafter referred to as the “subsequent inner region K”). In FIG. 10 is a plan view of the hole member 60, and FIG. 11 is a cross-sectional view along the line I-I indicated in FIG. 10. The bottom view of the hole element 60 is the same as the plan view.

[0051] The hole element 60 has a profile in the form of a perfect circle with a radius R (diameter 2R) in its plan view. The radius R is essentially the same as the radius r of the groove 50, or slightly less than the radius r. Therefore, the outer circular surface 62 of the hole element 60 is in contact with the inner circular surface 51a of the housing 51 without creating a gap between them, or is in sliding contact with the surface 51a.

[0052] As shown in FIG. 10, the hole 61 of the hole element 60, which forms the channel with the hole, has a composite figure outline that consists of circular holes 61a, 61b, 61c superimposed on each other, each of which has a radius R1, R2, R3, respectively. In the X-Y coordinate system (i.e., a horizontal rectangular coordinate system with a starting point on the central axis C), as shown in FIG. 10, the positions of the centers C1, C2, C3 of the respective circular holes 61a, 61b, 61c are shifted in the direction of the X axis and / or in the direction of the Y axis. Thus, with respect to the central axis C, the hole element 60, the center C1 of the circular hole 61a is shifted by + E1 in the direction of the X axis, the center C2 of the circular hole 61b is offset by the value -E2 in the direction of the X axis and + E3 in the direction of the Y axis, and the center C3 of the circular hole 61c is offset by the value -E2 in the direction of the X axis and the value of -E3 in the direction of the Y axis, and therefore, the centroid or center of gravity G of the composite figure formed by round holes 61a, 61b, 61c, is offset by + AE in the direction of the X axis. In the case where the eccentricity ratio η of the hole 61 is defined as the "eccentricity distance ΔE / radius r of the preceding region D", the eccentricity ratio η can preferably be set in the range equal to or greater than 0.06 (if required, in a range equal to or greater than 0.10). In the case where the eccentricity ratio η 'of the hole 61 is defined as the "eccentricity distance ΔE / maximum value Rmax", the value of the eccentricity ratio η' can preferably be set in the range equal to or greater than 0.1 (if required, in the range equal to or greater than 0.15), in which the maximum distance between the central axis C and the contour of the composite figure (edge of the hole 61) is defined as Rmax.

[0053] As shown in FIG. 11, the hole 61 is mounted horizontally at a height of H / 2, where H is the total height of the hole element 60. The inclined surfaces 68, 69 are formed in the form of a mortar or in a conical shape that extends between the hole 61 and the upper and lower circular edges 63, 64 of the outer circular surface 62.

[0054] As shown in FIG. 8 and 9, the hole element 60 is located in the lowest position of the cylindrical body 51. The bolt 58 is threaded to the hole 57 for the bolt of the housing 51 and the tip of the bolt 58 is pressed against the outer circular surface 62 by the clamping force of the bolt 58. The hole element 60 is fixed to the lowest portion of the housing 51 with a bolt 58.

[0055] A plurality of bolt holes 65 that are spaced apart from each other along a circle (shown by dashed lines in FIG. 8) are provided on the outer peripheral surface of the hole element 60. A rectangular opening 54 is provided in the lower portion of the peripheral wall of the housing 51, elongated along the circumference. The threaded end portion of the bolt 56 is engaged with the bolt hole 65 of the hole element 60, which is located in the region of the hole 54. The bolt 56 extends outward from the cylindrical body 51 through the hole 54. The hole element 60 can be rotated manually around the central axis C by temporarily releasing the clamping force of the bolt 58 and pressing on the portion of the head of the bolt 56 left or right. The directional property (anisotropy) or the relative position of the hole 61 can be changed relative to the tubular channel (inner preceding region D) by rotating the hole element 60, as a result of which the action intensity or the function of the axisymmetric rupture of the vortex can be controlled, or it can be controlled. In other words, the mechanism for rotating the hole element 60 (bolt hole 65, hole 54 and bolt 56) constitutes the cross-sectional control means for the channel through the hole, which allows you to alternately control or regulate the action or function of the axisymmetric rupture of the vortex flow in the channel with the hole.

[0056] Variation or adjustment of the cross section of the fluid channel as a result of rotation of the hole element 60 can be carried out not only before the operation of the mixer 10, but also during the operation of the mixer 10. When using such control means to control the cross section of the channel with the hole, perform delicate changes or fine adjustments to optimize the action or function of the channel with the hole by observing or measuring the state or physical property of the solution 3a flowing out of the mixer 10 to the bottom sheet 1. This is quite useful in practice. In accordance with the experiments performed by the inventors, the state or physical property of the solution 3 supplied to the bottom sheet 1 can be changed when the hole element 60 is rotated around the central axis C by at least 3 degrees. Therefore, the intensity of the action of the axisymmetric discontinuity of the vortex flow can be variably controlled, or it can be controlled by rotating the hole element 60 by an angle of at least 3 degrees.

[0057] As shown in FIG. 8, twisting power or rotational power is imparted to the solution flowing into the preceding inner region D due to the eccentricity of region D and the fluid channel 46. As a result, the solution flows downward by gravity, rotating around the inner surface of the round wall in region D, as shown in the form of a swirling tubular flow F (represented by dashed arrows in Fig. 9), resulting in an axisymmetric vortex flow in the form of a spiral or a cyclone flow is generated in region D. The direction of rotation of the solution (counterclockwise direction) is opposite to the direction γ of rotation of the rotating disk 32 (Fig. 5). The solution is subjected to mixing and stirring in the region D, due to its swirling motion. The radius of rotation of the swirling flow F gradually decreases as the cross section of the region D decreases due to the inclined surface 68 and the hole 61.

[0058] The configuration of the hole 61 in its plan view, which is a composite figure made up of circular holes 61a, 61b, 61c superimposed on each other, is non-axisymmetric with respect to the central axis C. In addition, the hole 61 has a center of gravity G, laterized by + AE in the direction of the X axis, as shown in FIG. 10. Therefore, the axisymmetric (rotationally symmetric) vortex flow, consisting of a swirling in-tube flow F, collapses in the hole 61. The radius of the swirling flow F after the channel through the hole 61 gradually increases, since the cross section of the fluid channel increases in accordance with the configuration of the inclined surface 69. As a result, swirl flow F regenerates its original configuration of swirl flow F in the subsequent region K. However, an axisymmetric swirl flow (swirl flow F the pipe inside) collapses in the hole 61 in such a way that the flow of the solution is distributed along the hole 61 or next to it. Therefore, a swirling flow, such as flow F, will not be regenerated in the subsequent region K, and a substantially weak swirling flow, which has a small rotational velocity component compared to swirling flow F, is simply regenerated in the flow region in the subsequent region K. Such swirling motion practically disappears during flowing through the transversely extending tubular section 74. Therefore, the flow of the solution, which has practically lost its rotational velocity component, flows through the outlet port 70 for release solution (Fig. 2) on the bottom sheet 1.

[0059] FIG. 12 and 13 are cross-sectional and longitudinal views of a trough 50 having an opening element 100, which is a comparative example in which the housing 20 and connector portion 47 are represented by imaginary lines (dashed lines).

[0060] A chute 50 having an opening element 100 with a conventional structure is shown as a comparative example in FIG. 12 and 13. Like the hole element 60, the hole element 100 has an external peripheral configuration, which is an ideal circle with a radius R (diameter 2R) in plan view, and its outer circular surface 102 is made so that it is in contact with the inner the round surface of the groove 50 without a gap between them, or in a sliding contact between them. The hole 101 of the hole element 100 has a contour 105, which is an ideal circle with a radius R1, the center of which is on the central axis C. The hole 101 is horizontally at a height H / 2, where H is the total height of the hole element 100, similar to the hole element 60 . The inclined surfaces 108, 109 formed in the form of a mortar or the shape of a conical surface extend from the upper and lower circular edges 103, 104 of the hole element 100 to the circular hole.

[0061] As presented above, the solution flowing into the previous inner region D is an axisymmetric vortex stream in the form of a spiral or cyclone stream, illustrated as a swirling in-tube flow F (shown by dashed arrows), which flows downward by gravity, swirling along the inner surface of the round wall of the region D. The radius of rotation of the swirling tubular flow F gradually decreases in the region D, since the cross section of the region D decreases due to inclination of the surface 108 and the hole 101. After the channel through the hole 101, the swirling flow F gradually increases its radius of rotation, since the cross section of the fluid channel increases due to the inclination of the surface 109, until the swirling in-tube flow, similar to the flow F, will not be restored in the subsequent region K. Thus, a swirling stream similar to the swirling stream F is regenerated in the flow field of the subsequent region K. Although the swirling stream F 'regenerated in the subsequent region K is is an axisymmetric vortex flow whose rotational velocity component is weakened compared to the flow F, the rotational velocity component F 'does not disappear when flowing through the tubular portion 74, and therefore, the rotational velocity component essentially remains in the solution discharge port 70 (FIG. 2). Thus, the rotating flow of the solution flows through port 70 (Fig. 2) to the bottom sheet 1.

[0062] FIG. 14-17 are graphical diagrams showing the results of tests obtained by measuring the distribution of the specific gravity of the gypsum core, compared with a gypsum board manufacturing apparatus having an opening member 60 (an embodiment of the present invention), as shown in FIG. 8-11, and a gypsum board manufacturing apparatus having an opening member 100 (comparative example), as shown in FIG. 12 and 13, respectively.

[0063] The inventors of the present invention obtained gypsum boards using an apparatus for producing gypsum boards with an opening member 60 mounted in a vertical groove 50 (an embodiment of the present invention). In addition, the authors of the present invention experimentally obtained gypsum boards using the same device with the usual hole element 100 (comparative example), which is installed instead of the hole element 60. The production conditions and proportions of mixing the materials were the same in these experiments. The resulting boards were standard gypsum boards, each of which was 910 mm wide, 1820 mm long and 12.5 mm thick.

[0064] FIG. 14 (C) and 14 (D) schematically shows a method for producing test samples for measuring the distribution of specific gravity. The inventors of the present invention cut out the middle part of the gypsum board M produced and isolated from it a zone in the width direction of the board having a length of 150 mm. In addition, the inventors cut off sections of the N lateral edge from the selected part, to remove areas with a large specific gravity obtained from the fractionated solution. The size of the portion N of the lateral edge was 50 mm. Such edge sections correspond to the edge sections of the gypsum board. Thus, the inventors obtained a test portion Q in the form of a rectangular plate, 810 mm long and 150 mm wide, as shown in FIG. 14 (D). The test portion Q thus obtained was cut into ten test pieces S (S1-S10), each 81 mm wide and 150 mm long, and the specific gravity of each of the S parts (S1-S10) was measured.

[0065] The specific gravity values actually measured with respect to the gypsum core are shown in FIG. 14 (A) and 14 (B), in which the measured test pieces S (S1-S10) were isolated from gypsum boards, which were experimentally produced in mixing ratios of materials and production conditions to set the specific gravity of the gypsum core to 0.7 (target value). In FIG. 14 (A) and 14 (B) on the horizontal axis represent the positions along the width of the gypsum board, which correspond to the corresponding test portions S1-S10, as shown in FIG. 14 (D), and the actual measured specific gravity values are shown on the vertical axis. In FIG. 14 (A) shows the results of testing a gypsum board obtained by a gypsum board manufacturing apparatus in which an opening member 60 is provided (an embodiment of the present invention), and FIG. 14 (B) shows the results of testing a gypsum board manufactured by the same device in which the hole member 100 was installed (comparative example).

[0066] As is apparent from the test results shown in FIG. 14 (A) and 14 (B), the specific gravity of the core obtained in the device with the hole element 100 (comparative example) varies significantly from 0.712 to 0.674 in the direction along the width of the plate, while the specific gravity of the core produced in the device with the element 60 holes (an embodiment of the present invention) varies only in the range of 0.697-0.694, and therefore, the specific gravity of the core represents a substantially constant distribution in the direction along the width of the plate (embodiment of the present invention). This means the following:

(1) In the case where the hole element 100 is used (comparative example), a relatively intense swirling flow is generated in the fluid channel on the side downstream of the hole 100, so that the solution tends to leak onto the paper sheet in a state in which mortar and foam are partially separated:

(2) On the other hand, in the case where an opening element 60 is used (an embodiment of the present invention), the solution flows through the discharge pipe 7 to discharge the solution onto the sheet in such a state that the separation of the solution and the foam is substantially completely eliminated.

[0067] FIG. 15-17, actually measured values of the specific gravity of the gypsum cores are shown in relation to test pieces S1-S10 isolated from the resulting plates, in which the gypsum plates were experimentally produced in mixing ratios of materials and under production conditions, to set the specific gravity of the cores of 0.6, 0.5 and 0.4 (target values). In each of FIG. 15-17, the diagrams indicated by the letter “(A)” show test results for gypsum boards produced by the apparatus with the hole member 60 (an embodiment of the present invention), and the diagrams indicated by the letter “(B)” show test results for gypsum boards produced using a device with a hole element 100 (comparative example).

[0068] As can be seen from the results of the experiments shown in FIG. 15-17, in the case where the hole element 100 is used (comparative example), the deviation of the specific gravity distribution is substantially increased when the target specific gravity of the core is set to or less than 0.6. In particular, when the target specific gravity is set to 0.4, the difference between the measured maximum value and the measured minimum value exceeds 15% of the target value. On the other hand, in the case where an opening element 60 is used (an embodiment of the present invention), the deviation of the specific gravity distribution does not increase, and therefore, gypsum boards having a substantially constant specific gravity distribution can be produced. For example, even when the target specific gravity of the core is set to 0.4, the difference between the measured maximum value and the measured minimum values is only about 2% of the target value. Therefore, the use of the hole element 60 is extremely effective for reducing the weight of the gypsum board.

[0069] FIG. 18 is a plan view showing outline modifications in plan of hole 61.

[0070] In the aforementioned embodiment, the contour of the hole 61 of the hole element 60 has a composite view composed of partially superimposed three holes 61a, 61b, 61c, each of which has a perfect circle shape. Alternatively, the contour of the hole 61 may be a single circle in the form of a perfect circle, which, in general, is shifted to offset the center (centroid G) of the hole 61 in an eccentric position relative to the central axis C, as shown in FIG. 18 (A). The centroid G of the hole 61 may be biased to an eccentric position relative to the central axis C, as a result of the deflection or deformation of the contour of the hole 61, as shown in FIG. 18 (B). Hole 61 may be a composite figure, which is a combination of two ideal circles (center C1: C2, radius R1: R2, eccentricity + E1: -E2), as shown in FIG. 18 (C), or a composite figure, which is a combination of four ideal circles (center C1: C2: C3: C4, radius R1: R2: R3: R4, eccentricity + E1: -E2: + E3, + E5: + E4, -E6), as shown in FIG. 18 (D). As can be seen from these modifications, the design of the contour of the hole 61 can be accordingly modified without going beyond the scope of the invention.

[0071] The central circular regions Umin are shown in FIG. 18, each of the circles is an ideal circle with a radius Rmin, the center of which is on the central axis C. The relationship between the non-circular contour of the hole 61 and the central circular region Umin is shown in FIG. 19 (A). As shown in FIG. 19 (A), the hole 61 contains a region Umin with a radius Rmin, and the hole 61 is contained in a maximum circular region Umax in the form of a perfect circle having a radius Rmax. Preferably, the radius Rmin is set to or greater than 0.15 x radius r, and the radius Rmax is set to or less than 0.85 x radius r. Therefore, the contour of the hole 61 can vary in the range from 0.15r to 0.85r, preferably in the range from 0.2r to 0.8r, where "r" is the radius mentioned above.

[0072] FIG. 19 (B) shows a state in which an ideal circle hole 61 having a radius R1 is substantially offset from the central axis C. The central axis C1 (centroid G) of the hole 61 is located in the annular zone, in the range from 0.2r to 0, 8r, and therefore, the central circular region Umin is not contained in the hole 61, and the region Umin extends beyond the hole 61. However, in this state, a spiral or cyclone axisymmetric vortex flow is preferably generated in the previous inner region D. This means that the axisymmetric whirlwind nd stream for mixing the solution and the foam may be generated in the region D, even if the hole contour 61 substantially deformed, or substantially center of the hole 61 is offset from the center. However, even if the region Umin extends beyond the opening 61, it is preferable that the central axis C is located within the opening 61.

[0073] FIG. 20 is a partial perspective view showing configurations of edge portions of holes 61. Hole 61 shown in FIG. 20 (A) has an edge portion 67 in a linear shape or in a shape extending through its entire circumference, and in the hole 61 shown in FIG. 20 (B), inclined surfaces 68, 69 are provided, each of which has a predetermined constant angle of inclination over its entire circumference. In the case where the hole 61 has an edge portion 67 in a linear shape or in the shape shown in FIG. 20 (A), the angle of inclination in each of the surfaces 68, 69 changes in accordance with the contour of the hole 61. On the other hand, when each of the inclined surfaces 68, 69 has a predetermined constant angle of inclination, the edge 66 in the form of a flat bevel is inevitably formed at least partially, in the region of the edge of the hole 61. On such an edge 66 in the form of a flat facet, a tendency is observed in accordance with which a dense mass of gypsum mortar is formed and poured to it due to stagnation and solidification of the mortar. Therefore, from the viewpoint of preventing sticking of the hardened mass of the solution in the hole 61, in the hole 61, an edge portion 67 is preferably provided in a linear shape or in the shape shown in FIG. 20 (A).

[0074] FIG. 21 is a schematic perspective and cross-sectional view showing an arrangement of a change in position of the central axis C of the tubular channel as a result of variation or lateralization of the cross section of the fluid channel.

[0075] As presented above, two methods for supplying the solution from the mixer 10 without using a trough are known in the art, one of which is a method in which a channel for transporting the solution, such as a tubular channel 47 ′, as shown in FIG. 5 is transversely connected to the solution supply port on the annular wall 23 of the housing 20 so that the solution is fed directly to the bottom sheet 1 under the action of the supply pressure of the mixer 10, and the other is a method in which a solution supply channel, such as pipes a channel 47 ", such as that shown in Fig. 6, is vertically connected to the solution feed port of the lower plate 22 of the housing 20 so that the solution in the mixer 10 is directly fed to the lower sheet 1 by gravity. The concept of the present invention is applicable to tubular channels in these methods, and such arrangements are shown schematically in Fig. 21. If desired, a gutter similar to the aforementioned gutter 50 can accordingly be installed in the channel for transporting the solution or in the channel for supplying the solution.

[0076] The tubular channel 90, as shown in FIG. 21 (A) generally has a perfect circle cross-section, but fluid channel portions 91, 92 are locally provided in channel 90, each of which has a non-axisymmetric cross section with respect to the center axis C of channel 90. Each of portions 91, 92 the channels shown in FIG. 21 (A) has an elliptical cross section, the main axis of which is directed vertically or horizontally. This results in at least partial rupture of the axisymmetric vortex flow F, obtained as a swirling in-tube flow, so that the swirling flow on the downstream side of the channel section 91, 92 does not restore its state on the previous side of the channel sections 91, 92 or the swirling flow is not regenerated on the downstream side of the channel portion 91, 92.

[0077] The tubular channel 95, as shown in FIG. 21 (B) includes tubular portions 96, 97, each of which has an ideal circular cross section. The radius R1 of the channel portion 96 is different from the radius R2 of the channel portion 97. A duct portion 97 having a relatively small radius is lateralized on one side (lower side in FIG. 21 (B)) on the connecting portion (fluid duct portion) 98 between the tubular duct portions 96, 97. The axial lines C1, C2 of the sections 96, 97 of the tubular channel are offset from the center on the connecting part 98 (eccentricity + AE), and therefore, at least partial rupture of the axisymmetric vortex flow F, which forms as a swirling in-tube flow, results such a change or lateralization of the cross section of the fluid channel. As a result, the flow on the downstream side of this portion of the fluid channel does not restore its state on its previous side, or the swirling flow does not occur on the side downstream of the portion of the fluid channel. Alternatively, a relatively large diameter tubular duct portion 97 '(radius R2') may be connected to the duct tubular portion 96 in the connecting portion (fluid duct portion) 99, as shown by dashed lines in FIG. 21 (B) in such a way that the center lines C1, C2 'of the channel sections 96, 97' are offset from the center (eccentricity - AE ') on one side (the upper side in Fig. 21 (B)). In addition, another portion 96 of the tubular channel and the like. can be connected to the subsequent end of the channel section 96, 97 ', so that it forms a reduced or enlarged section locally or at the transition using channel sections 96, 97'.

[0078] Although the present invention has been described as preferred embodiments and examples, the present invention is not limited thereto, but it can be made in any of various modifications or variations without departing from the scope of the invention as defined in the attached claims.

[0079] For example, the arrangement of the device in accordance with the present invention can equally be applied to a mixer other than a pin type mixer, such as a pinless mixer (paddle type mixer and the like).

[0080] Furthermore, the cross section of the channel inside the chute pipe, the transport channel, or the feed channel is not limited to a strictly perfect circle, but it can be a circle having to some extent alternation, distortion, local deformation, etc. If desired, the central axis of the trough can be tilted relative to the vertical direction, or the trough can communicate with the mixing area of the mixer through a pipe, such as a flexible pipe.

[0081] Furthermore, the mixer in the above embodiment has a fractionation port for a solution having a relatively large specific gravity, but the present invention is applicable to a mixer without a fractionation port, or a mixer that delivers a solution having a relatively small specific gravity, through a fractionation port .

[0082] In addition, the mixer in the above embodiment is configured to supply foam to the solution in the hollow portion of the connector, but the foam may enter the solution in the groove or in the mixing area. In addition, the mixer in the aforementioned embodiment is configured such that the foam formed by the formation of the foam by the foaming agent in the foam generating means enters the solution, but the foaming agent can be directly fed into the solution so that the foam will form in the solution under its action, foaming in solution. If desired, the direction of rotation of the solution in the trough can be set in the opposite direction to that shown in FIG. 5, as a result of a change in the ratio of positions between the part of the hollow connector and the groove.

[0083] Further, the hole in the hole element that forms the channel with the hole is horizontally arranged to alter or lateralize the cross section of the fluid channel in the above embodiment. However, the orifice may be altered or lateralized by inclining the orifice in general or in part, or the angle of inclination of the orifice may be varied relative to the horizontal plane to change or lateralize the cross section of the fluid channel, thereby changing the position of the central axis of the tubular channel. In the case when the cross section is changed or lateralized as a result of such a change in angle, a variable setting of the angle of inclination is required, at least 3 degrees.

Industrial applicability

[0084] The present invention can be applied to a mixing and stirring device, in a mixing and stirring method, and in a method for producing lightweight gypsum boards. In accordance with the present invention, the rotational movement of the gypsum mortar poured onto a sheet of paper used as a coating for a gypsum board can be limited, which prevents the occurrence of incorrect distribution, deviation or irregular dispersion in the distribution of the specific gravity of the solution on the paper sheet.

[0085] The present invention is very effective in the production of lightweight gypsum boards having a specific gravity of 0.4-0.7, since a uniform density distribution of the gypsum core can be ensured. Therefore, given the tendency to reduce the weight of gypsum boards in recent years, the advantages of the present invention are significant in practice.

List of Reference Numbers

[0086] 1 bottom sheet of paper

2 top sheet of paper

3 solution

4 section of solution supply

5 continuous three-layer tape configuration

7 solution feed pipe

8 piping for fractionation

10 mixer

20 case (casing)

23 ring wall

40 foam supply line

41 foam supply ports

45 output port for mortar

46 channel for fluid solution

47 hollow connecting part

50 gutter

51 cylindrical body

54 hole

55 top hole

56.58 bolt

57, 65 bolt hole

60 hole element

61 holes (channel with hole)

62 outer round surface

63 round edge

68, 69 inclined surface

70, 80 port for the release of the solution

90, 95 tubular channel

91, 92 section of the fluid channel

96, 97, 97 ’section of the tubular channel

98, 99 connecting part (portion of the fluid channel)

C central axis

D intratubular region inside the gutter (anterior inner region)

F swirling round pipe

G channel centroid with hole

H the total height of the hole element

K intratubular region in the pipe for supplying the solution (subsequent inner region)

P powder materials

L liquid (water)

M foam

r, R radius

Claims (33)

1. A mixing and mixing device (10) for gypsum mortar, which has a round body (20) forming a mixing region (10a) for mixing gypsum mortar (3), a rotating disk (32) installed in the housing and rotated in a predetermined direction ( γ) rotation, and a tubular channel (7, 47, 50) for supplying gypsum mortar, which is provided outside the housing for supplying mortar from the mixing area to the sheet of coating paper (1) of the gypsum board and which generates an in-tube swirling flow (F) for mixing gypsum mortar with foam oh or foaming agent (m) for regulating the specific gravity, moreover, the said tubular channel includes a chute (50), which receives a gypsum mortar flowing out of the housing (20) through the outlet port (45) for the solution provided in the housing, and through which the solution (3) flows down it under the force gravity, and a discharge pipe section (7) connected to the outlet of the trough for pouring the solution onto said sheet of paper; wherein said trough has a channel (61) with an opening that locally limits the cross section of the intratubular region (D) of the trough to allow gypsum mortar and foam or foaming agent to rotate in the intratubular region; and moreover, the centroid (G) of the cross-sectional view of the channel (61) with the hole is located in a position eccentric with respect to the central axis (C) of the said in-tube region. 2. The device according to claim 1, in which the eccentricity ratio η = ΔE / r of said centroid (G) is set equal to or greater than 0.06 and in which ΔE is the distance between said centroid and said central axis (C) of the tubular region ( D), and r represents the radius of the in-tubular region. 3. The device according to p. 1 or 2, in which the contour of the cross section of said channel (61) with an aperture is a composite figure consisting of a plurality of figures partially superimposed on each other, and the centroid (G) of the composite figure is made eccentric relative to the central axis (C) of said in-tube region (D). 4. The device according to claim 3, in which said composite figure is composed of many circles (61a, 61b, 61c) having different diameters (R1, R2, R3) and / or different central positions (C1, C2, C3), circles superimposed on each other only partially. 5. The device according to claim 1, in which the eccentricity ratio η΄ = ΔE / Rmax is set equal to or greater than 0.1 and in which ΔE represents the distance between said centroid (G) and the central axis (C) of said in-tube region, and Rmax is the maximum value of the distance between the said central axis and the contour of the figure. 6. The device according to claim 1, wherein the supply port (44) that delivers the foam or foaming agent (m) to said solution is located on the annular wall (23) of said housing (20) for supplying foam or foaming agent to the solution directly before the solution flows from said mixing region (10a) into said solution outlet port (45), or it is provided on part (47) of the hollow connector between the trough (50) and the outlet port (45) for the solution for supplying foam or foaming agent to solution immediately after flow the mixture from the mixing area through the outlet port for the solution. 7. The device according to claim 1, in which the element (60) with an opening having said channel (61) with an opening is located in said trough (50), and the element (60) with an opening has regulating means (54, 56, 65 ) to control the cross section of the channel for the fluid, which rotates or moves the element with the hole to control or control the intensity of the rupture of the axisymmetric vortex flow in the channel with the hole. 8. A method for mixing and stirring a gypsum mortar using a device (10) for mixing and stirring a gypsum mortar having a round body (20), forming a mixing area (10a) for mixing gypsum mortar (3), a rotating disk (32) mounted in the housing and rotating in a predetermined direction (γ) of rotation, and a chute (50) for supplying gypsum mortar supplied outward from the housing, for supplying the solution from the mixing area to a sheet of paper, for coating (1) the gypsum board, and which generates an in-tube swirling flow (F) for mixing the solution with foam and foaming agent (m) to control the specific gravity, moreover, the solution flowing out of the housing through the outlet port (45) for the solution located on the housing is forced to flow down under the action of gravity in the intratubular region (D) of the trough, and the foam or foaming agent (m) is mixed into the solution by means of the said intratubular swirl the flow (F) generated in the tubular region, and the solution is fed from the trough to the outlet pipe section (7) through a channel (61) with an opening that locally limits the cross section of the tubular region, and moreover, the centroid (G) in the form of a cross-section of the channel with the hole is located in a position eccentric with respect to the central axis (C) of the said tubular region, so that the axisymmetric vortex flow in the tubular region is interrupted by the channel with the hole to limit recovery or generation intratubular swirling flow (F ') in the said section of the exhaust pipe on the side downstream of the channel with the hole. 9. The method according to p. 8, in which the eccentricity ratio η = ΔE / r of said centroid (6) is set equal to or greater than 0.06, and ΔE is the distance between said centroid and said central axis (C) of the tubular region, and r is the radius of the in-tubular region (D). 10. The method of claim 8 or 9, wherein the cross-sectional contour of said channel (61) with an aperture is a composite figure consisting of a plurality of figures (61a, 61b, 61c) partially overlapped and the centroid of the composite figure is made eccentric with respect to the central axis (C) of said tubular region. 11. The method according to p. 10, in which said composite figure is composed of many circles (61a, 61b, 61c) having different diameters (R1, R2, R3) and / or different central position (C1, C2, C3), circles superimposed on each other only partially. 12. The method of claim 8, wherein the eccentricity ratio η΄ = ΔE / Rmax is set to or greater than 0.1, and ΔE is the distance between said centroid (G) and the central axis (C) of said in-tubular region, and Rmax is the maximum value of the distance between the said central axis and the contour of the figure. 13. The method of claim 8, wherein the amount of foam or foaming agent (m) supplied to said gypsum solution (3) is set to a value according to which the specific gravity of the gypsum core of the gypsum board is in the range of 0.4 up to 0.7. 14. The method according to claim 8, in which the intensity of the rupture of the axisymmetric vortex flow of the channel (61) of the hole is controlled or controlled by changing or lateralizing the position or cross-sectional configuration of the said channel with the hole. 15. A method for the production of lightweight gypsum boards having a specific gravity equal to or less than 0.8, in which the gypsum mortar (3) is obtained through the use of a mixing and stirring device for gypsum mortar (10), which has a round body (20) forming a mixing area (10a) for mixing gypsum mortar, a rotating disk (32) installed in the housing and rotating in a predetermined direction (γ) of rotation, and a tubular channel (4, 47, 50) for supplying the gypsum mortar led out from housing, for supplying mortar ora from the mixing area onto the sheet of paper to cover (1) the gypsum board, and wherein the solution from the mixing area is poured onto the sheet of paper through the groove (50), which allows the solution to flow down under gravity, comprising the following steps: a gypsum solution of the mixing region, flowing out of the housing, is fed through the solution outlet port (45) located on the housing into the tubular channel (D) of the said trough together with foam or foaming agent (m) for controlling the specific gravity, and an in-tube swirling flow is generated (F) in the intratubular region (D) of the trough by rotating the solution therein so that the solution and the foam or foaming agent are mixed in the tubular channel by the intratubular swirling flow generated in the trough; and a gypsum solution is introduced from the chute into the outlet pipe section (7) through a channel (61) with an opening that locally limits the cross section of the fluid channel in the in-tube region, and set the centroid (G) of the cross-sectional view of the channel with the hole in the position eccentric relative to the central axis (C) of the intratubular region to break the axisymmetric vortex flow in the intratubular region due to the channel with the hole, thereby restricting the recovery or generation of the intratubular swirl flow (F΄ ) in the intratubular region (k) of the said section of the exhaust pipe located on the side downstream of the channel with the hole. 16. The method of claim 15, wherein the eccentricity ratio η = ΔE / r of said centroid (G) is set equal to or greater than 0.06, and ΔE is the distance between said centroid and said central axis (C), and r represents the radius of the tubular region (D). 17. The method of claim 15 or 16, wherein the cross-sectional contour of said channel (61) with an aperture is a composite figure consisting of a plurality of figures (61a, 61b, 61c) partially overlapped and the centroid of the composite figure is made eccentric with respect to the central axis (C) of said tubular region. 18. The method according to p. 15, in which the eccentricity ratio η΄ = ΔE / Rmax is set equal to or greater than 0.1, and ΔE is the distance between said centroid (G) and the central axis (C) of said in-tube region (D ), and Rmax represents the maximum value of the distance between the said central axis and the contour of the figure. 19. The method according to p. 15, in which the amount of foam or foaming agent (m) supplied to said gypsum mortar (3) is set to a value according to which the specific gravity of the gypsum core of the gypsum board is in the range from 0.4 up to 0.7. 20. The method according to p. 15, wherein said mixing and stirring device (10) has adjusting means (54, 56, 65) for adjusting the cross section of the fluid channel, which changes the position or configuration of the channel (61) with an opening relative to said troughs (50) for regulating or controlling the action of rupture of an axisymmetric vortex flow of a channel with a hole, and the intensity of said action is controlled or controlled by said regulating means, during operation of said device, in in accordance with the state or physical property of the gypsum solution supplied to the sheet of paper (1). 21. The method according to p. 15, wherein said foam or foaming agent (m) is fed into the solution (3) immediately before or after the solution flows from the mixing area through the solution outlet port. 22. A device for the production of lightweight gypsum boards, which has a device (10) mixing and stirring according to any one of paragraphs. 1-7. 23. A method of manufacturing a lightweight gypsum boards, in which gypsum boards having a specific gravity in the range from 0.4 to 0.7 are produced using the method according to any one of claims. 8-14.

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